Method for actuating valves for controlling a flow path and machines, especially medical treatment machines

ABSTRACT

A method is provided for the control of valves for flow path control, in particular in a medical treatment machine, having a plurality of processes for the manufacture of flow paths by control of a group of valves, with each process claiming a group of valves suitable for its carrying out for itself so that other processes cannot change the switching state of these valves and with each process itself making a decision on the release of the valves claimed by it. In addition, a method is provided for monitoring the then current and/or scheduled state of a plurality of valves in the flow path control, determining the connections resulting from the switching state of the valves, and comparing the resulting connections with a predetermined number of non-permitted connections.

This is a continuation application of U.S. patent application Ser. No.12/735,889, filed Aug. 24, 2010, issusing as U.S. Pat. No. 8,634,964 onJan. 21, 2014, which was a national stage of PCT/EP2009/001381 filedFeb. 26, 2009 and published in German, which had a priority of Germanapplication no. 10 2008 011 827.3 filed Feb. 29, 2008, and hereby claimsthe priority thereof to which it is entitled.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for the control of valves forflow path control, in particular in a medical treatment machine. Thepresent invention furthermore relates to a method for the monitoring ofthe then current and/or scheduled state of a plurality of valves in flowpath control, in particular in a medical treatment machine, as well asto a machine, in particular a medical treatment machine, having acontrol for the carrying out of the corresponding methods.

The present invention in particular relates to methods for the operationof a machine in which a cassette system is used for the transport ofliquids, in particular medical liquids. The present invention is usedparticularly advantageously in treatment machines in the field ofdialysis, in particular in the field of peritoneal dialysis. Cassettesystems are usually used in such treatment machines for the transport ofthe treatment liquids or for the carrying out of the treatment.

The present invention in particular relates to peritoneal dialysismachines such as are presented in US 2007/0112297 A1 and US 2006/0195064A1 as well as to methods for the operation of such peritoneal dialysismachines. The full extent of the content of 2007/0112297 A1 and US2006/0195064 A1 is hereby an integral part of the disclosure of thepresent application.

2. Description of the Related Art

The disposable cassettes used in such cassette systems have fluid pathsand valve points via which the flow paths required for the respectivetreatment step can be established in the cassette. The fluid paths ofthe cassettes are usually formed by liquid conducting passages whichhave at least one flexible wall in the region of the valve points. Theflexible wall can then be pressed into the liquid conducting passage bya valve actuator and so block said passage. Pneumatically actuableactuators can e.g. be used as the actuators which expand on theapplication of pressure to the actuator and so serve as valve tappets.Hydraulic or electric motor valve actuators can equally be used. Theliquid conducting passages with the valve points are usually arranged atthe disposable cassette; the valve actuators at the treatment machine.The cassettes are then inserted into the treatment machine and coupledto it so that the valve actuators at the treatment machine come intoengagement with the valve points at the cassette and determine theswitching state of the valves of the cassette.

Programs are usually stored in the machine control for the control ofthe valves and the group of valves required for the establishing of arequired flow path (e.g. from a pump chamber to the patient) arecontrolled via said programs. A flow path is in this context understoodas the connection between two sources and/or sinks which are connectedby valves, e.g. the connection between a bag and a pump which isestablished by opening the valves disposed between the bag and the pumpas well as closing valves to other component conducting connectionlines. A plurality of valves are usually provided, e.g. nine or sixteenvalves in known systems, via whose different control a plurality ofdifferent flow paths between the patient, the pump chambers of thecassette and different bags with liquid or for drainage can beestablished.

In known methods, a flow path which is e.g. required for a certain pumpcycle is fixedly predetermined by the method used. In this connection,the machine knows the corresponding flow path for the method used sinceit is fixedly stored in the application. If the method now requires aconnection from a point A to a point D, which could theoretically takeplace both via B and via C, this connection is previously stored in theapplication—e.g. via B. The application therefore does not have a freechoice, but rather has a fixedly stored connection assigned to it in thepresent case.

A monitoring of the permitted flow path A-B-D is not necessary in thisrespect since only permitted and previously fixed connections are storedin the protection system. The flow paths required for a completeapplication are thus stored on the programming of the methods. If now anew method should be integrated into the application of the machine, theflow paths required for this must be checked as to whether they arestored in the protection system or whether they have to be stored asnew, which has to result in a total check since the change betweenindividual flow paths to be switched possibly also has to be checked formeaningfulness. A further disadvantage of the previously known systemsis furthermore the change between two preset pump cycles since all thevalves first have to be closed for this purpose for safety reasons. Thisresults in an increase in wear in the valve components. The knownsystems are therefore inflexible and make the implementation of newmethods difficult.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide methods for thecontrol or monitoring of valves for flow path control in which theimplementation of new methods is made more flexible, with the necessarysafety aspects nevertheless being taken into account. It is furthermorethe object of the present invention to provide machines, in particularmedical treatment machines, having corresponding valve controls or valveactuator controls.

This object is solved by a method for the control of valves for flowpath control, in particular in a medical treatment machine, having aplurality of processes for the establishing of flow paths by controllinga group of valves, wherein each process claims a group of valvessuitable for its carrying out for itself so that other processes cannotchange the switching state of these valves; and wherein each processitself makes a decision on the release of the valves claimed by it. Thisobject is also solved by a method for the monitoring of the then currentand/or scheduled state of a plurality of valves in the flow pathcontrol, in particular in a medical treatment machine, having the stepsof determining the then current and/or scheduled switching state of thevalves; determining the connections resulting from the switching stateof the valves; and comparing the resulting connections with apredetermined number of non permitted connections.

The object is further solved by a machine, in particular a medicaltreatment machine, having a plurality of valve actuators for the controlof valves for the flow path control, in particular in a cassette system,with a valve actuator control for the carrying out of a plurality ofprocesses for establishing flow paths by controlling a group of valveactuators, with the valve actuator control being configured such thateach process claims a group of valve actuators suitable for its carryingout for itself so that other processes cannot change the switching stateof these valve actuators and each process itself makes a decision on therelease of the valve actuators claimed by it. Still further, the objectis solved by a machine, in particular a medical treatment machine,having a plurality of valve actuators for the control of valves for theflow path control, in particular in a cassette system, having a valveactuation control and having a monitoring unit for the monitoring of thethen current and/or scheduled state of a plurality of valves, with themonitoring unit determining the then current and/or scheduled switchingstate of the valves and the connections resulting from the switchingstate and comparing the resulting connections with a predeterminednumber of non permitted connections.

The present invention includes a method for the control of valves forflow path control, in particular in a medical treatment machine, havinga plurality of processes for the manufacture of flow paths by control ofa group of valves, with each process claiming a group of valves suitablefor its carrying out for itself so that other processes cannot changethe switching state of these valves and with each process itself makinga decision on the release of the valves claimed by it. It is possible,on the one hand, by this method to allocate valves or groups of valvesto individual processes in a flexible manner.

In this context, a process represents a method constituent within thevalve control of the machine which provides a certain flow path. Forthis purpose, a process requires a group of valves whose switching stateit sets thus that the valves establish the flow path. This group ofvalves usually only represents some of all the valves so that a processusually does not claim all valves for its carrying out. In thisconnection, there can be a plurality of different possibilities ofrealizing a flow path for the same flow path, e.g. from a pump chamberto a bag, i.e. a process can be realized by different groups of valves.

It is now possible by the method in accordance with the invention thatindividual processes flexibly claim different groups of valves withoutimpairing the safety of the system. While one process claims the groupof valves required for the establishing of the flow path, otherprocesses cannot change the switching state of these valves so that onlythe process providing a flow path can also make a decision on itscancellation.

In this context, each process makes a decision on the release of thevalves claimed by it in accordance with internal and/or external processcriteria. Internal process criteria can e.g. be pump positions, stepsalready carried out or the completion of the process. Externalcircumstances can e.g. be a higher prioritization of another process. Itis, however, decisive in the present method that only the processrespectively claiming the valves can also release them again so that acoordinated and reliable interplay of a plurality of processes isensured.

In this connection, each process advantageously releases the claimedgroup of valves after its ending. These valves can hereby in turn againbe claimed by other processes and used for carrying them out.

Advantageously, a process can in this connection claim different groupsof valves depending on the availability of the valves. This enables aflexible valve management in which the available resources are ideallyutilized. In this connection, in a first method variant, a valve isconsidered as available for a process if it is not claimed by any otherprocess. A valve can thus, however, always only be claimed by a singleprocess even if two processes actually require the same switching statefor a valve and are therefore basically compatible.

In a second method variant, a valve is therefore considered as availablefor a second process when it is not claimed by any other process or whenit is admittedly already claimed by a first process, but has theswitching state required by the second process. The switching state ofsuch a valve already claimed by a first process can no longer be changedby the second process in this connection. If this is, however, notnecessary for the establishing of the flow path by the second process,the second process can then use this valve. For this purpose, the secondprocess advantageously also claims the valve so that its switching statecan also no longer be changed by the first process. Both processes canthus utilize the same valve, with an unintentional cancellation of theflow path of the one process by the other process being prevented by theclaiming of the valve.

In this connection, the individual processes advantageously representmethod constituents within the valve control of the machine whichestablish a specific flow path and maintain it up to their end. Thechanging of a flow path thus always takes place by the carrying out of anew process.

In this connection, in accordance with the invention, each processadvantageously polls the availability of a group of valves suitable forits carrying out before its carrying out. A process which wants toestablish a certain flow path thus initially polls whether a group ofvalves suitable for this purpose is already available.

A process is advantageously carried out in this connection when asuitable group of valves is available, with the process claiming thisgroup of valves for itself. If therefore such a group of valves isavailable, the process can be carried out independently of furtherprocesses possibly running in parallel. It is sufficient for thispurpose for a combination of valves to be available from a plurality ofpossible combinations of valves which are suitable for the establishingof the desired flow path. If, however, the desired flow path cannot beestablished with the available valves, the process can thus initiallynot start.

Advantageously, the polling of a non-available valve by a second processresults in a request to the first process claiming this valve to releasethis valve, with only the first process making a decision on thisrequest. This is in particular the case if no suitable group of valvesis available for the carrying out of the second process. The secondprocess then requests the first process to release the valve it needs.The first process now makes an independent decision on this request,with internal and external process criteria being able to be taken intoaccount. Only when the first process has released the required valve orthe required group of valves can the second process change theirswitching state and establish the desired fluid path.

In this connection, the polling process advantageously claims all of thepolled and available valves for itself. It is hereby ensured in aplurality of processes that a process can initially claim all theavailable valves for itself and thus only has to wait for the valveswhich have to be released by other processes so that it can change theirswitching state.

Advantageously, the polling process furthermore receives a right toclaim all polled but not available valves on the polling so that it canclaim these valves for itself when they have been released. A reliabletransition from one process to the next is hereby possible even with aplurality of processes. In particular different priority rights can beawarded for different processes in this connection.

Advantageously, the method in accordance with the invention includes acentral valve allocation process in which all the other processes claim,release and/or request the required valves. This central valveallocation process thus takes over the distribution management for theindividual valves and valve groups, with the release of individualvalves, however, only being able to take place by the process which isthen currently utilizing them.

The method in accordance with the invention advantageously includes thefollowing steps: claiming a first group of valves for the carrying outof a first process in which a first flow path is established by controlof the associated first group of valves; polling the availability of asecond group of valves for the carrying out of a second process in whicha second flow path should be established by control of the associatedsecond group of valves; and carrying out the second process when allrequired valves are available, with the polling of valves which are notavailable by the second process resulting in a request to the firstprocess to release these valves, with only the first process making adecision on this request.

The present invention thus permits a flexible flow path planning. A flowpath in this connection is understood as the connection between twosources and/or sinks which are connected by valves, e.g. the connectionbetween a bag and a pump. If such a flow path is made available by afirst process, the valves controlled for this purpose are claimed bythis first process and their switching state of can no longer be changedby further processes to establish other flow paths. If now a specificflow path is requested by a second process, e.g. by a second pump cycleof the process, all the valves required for the flow path are thenpolled. The available valves can be claimed. The valves which arealready assigned to the first process, e.g. a first pump cycle, andwhose switching state would have to be changed, are requested in thisfirst process. The first process has sole power of decision on when andif it releases the valves to the second process. As soon as thecorresponding valves have been released by the first process, therequesting second process can use the valves and form its flow path.

To prevent an unwanted free flow on a change from a first process to asecond process, the required valves which are already in the correctstate for the corresponding process are left in their state. It appliesto the valves whose state has to be changed that the valves to be closedare closed in a first step. In a second step, the valves required by thesecond process in an open state are opened.

It is possible by this method in accordance with the invention for thecontrol of the valves that a plurality of processes access theindividual valves in a flexible manner, with a reliable operationnevertheless being ensured by the release rules in accordance with theinvention. This flexible and open architecture of the processes inaccordance with the invention makes it possible to implement newprocesses particularly simply. In particular the complete systemarchitecture no longer has to be revised for this purpose. It is ratherthe case that new processes can be added to the existing processeswithout problem.

There are thus additionally substantially fewer valve switchingprocesses and thus a lower wear of the valve components by this type ofthe flow path formation in the flexible design of the implementation ofnew processes which can run on the treatment machine, e.g. a cycler.Such a cycler represents a treatment machine for dialysis, in particularfor peritoneal dialysis, which permits an automated exchange of thedialysis liquids. It is in particular possible to dispense withinitially closing all valves on a change between pump cycles, as isstill necessary in the prior art for safety reasons.

The present invention in this connection furthermore includes a machine,in particular a medical treatment machine, having a plurality of valveactuators for the control of valves for the flow path control, inparticular in a cassette system, with a valve actuator control for thecarrying out of a plurality of processes for establishing flow paths bycontrolling a group of valve actuators, with the valve actuator controlbeing configured such that each process claims a group of valveactuators suitable for its carrying out for itself so that otherprocesses cannot change the switching state of these valve actuators andeach process itself makes a decision on the release of the valveactuators claimed by it. Valves which are in particular arranged in acassette system which is inserted into the machine are controlled viathe valve actuators to make corresponding flow paths available in thecassette. The same advantages result from such a machine such as werealready described with respect to the method. It is in particular herebypossible to associate different groups of valve actuators to theindividual processes in a flexible manner without impairing the safetyof the system. The valve actuator control in accordance with theinvention is in particular programmed such that the processes inaccordance with the invention can be carried out in accordance with theinvention, with the method in accordance with the inventionadvantageously running automatically on the machine in accordance withthe invention.

In this process, in accordance with the invention, each processadvantageously makes a decision on the release of the valve actuatorsclaimed by it in dependence on internal or external process criteria. Asalready described with respect to the method, the safety of operation ofthe machine is hereby ensured.

In this connection, each process advantageously releases the claimedgroup of valve actuators after its end. The latter can thereby againhave their switching states changed by other processes.

In this connection, a process can advantageously claim different groupsof valve actuators in dependence on the availability of the valveactuators. A flexible association of different groups of valve actuatorsto a process is hereby possible so that different groups of valveactuators can be controlled by the same process for the establishing ofa flow path.

Each process advantageously polls the availability of a group of valveactuators suitable for its carrying out before its carrying out. Aprocess is carried out in this connection when a suitable group of valveactuators is available, with the process claiming this group of valveactuators for itself. It is hereby ensured that other processes can nolonger change the switching state of this group of valve actuators sothat only the process itself can make a decision whether the flow pathprovided by it is maintained or cancelled.

Advantageously, the polling of a non-available valve actuator by asecond process results in a request to the first process claiming thisvalve actuator to release this valve actuator, with only the firstprocess making a decision on this request. A poll in particular resultsin a request to release a valve actuator when no group of valveactuators is available with which the second process could establish theintended flow path. In this case, the flow path provided by the firstprocess first has to be cancelled to be able to form the flow path to beprovided by the second process.

In this connection, the polling process advantageously claims all of thepolled and available valve actuators for itself. The available valveactuators, that is all the valve actuators not claimed by anotherprocess and, advantageously, all the valve actuators claimed by otherprocesses, but already being in the desired switching state, can herebybe claimed by the polling process for itself so that the switchingprocess of these valve actuators can no longer be changed by otherprocesses.

Further advantageously, the polling process furthermore receives a rightto use with respect to all polled but not available valve actuators onthe polling so that it can claim these valve actuators for itself whenthey have been released. If therefore the switching state of a valveactuator already claimed by another process has to be changed, thepolling process does not claim this valve for itself, but only receivesa claim right to it which it can exercise when this valve actuator hasbeen released by the first process. A synchronization of a plurality ofdifferent processes is hereby possible.

The valve actuator control advantageously includes a central valveassociation process in which all the other processes can claim, releaseand/or poll the required valve actuators.

The valve actuator control in accordance with the invention isadvantageously programmed such that the following steps can be carriedout: claiming a first group of valve actuators for the carrying out of afirst process in which a first flow path is established by control ofthe associated first group of valves; polling the availability of asecond group of valve actuators for the carrying out of a second processin which a second flow path should be established by control of theassociated second group of valves; and carrying out the second processwhen all required valve actuators are available, with the polling ofvalve actuators which are not available by the second process resultingin a request to the first process to release these valve actuators, withonly the first process making a decision on this request.

The machine in accordance with the invention advantageously has acoupling surface for the coupling of a cassette, with the cassetteincluding passages having valves and conducting liquids and with thevalve actuators on the machine side for the establishing of differentflow paths in the cassette determining the switching state of the valveson the cassette side. In this connection, the valve actuators areadvantageously arranged on the coupling surface of the machine. Thecassette usually represents a disposable part which is inserted into themachine.

In accordance with the invention, a method thus results as well as acorresponding machine on which the flow path formation can beimplemented with much greater flexibility.

The safety system should also be adapted to the flexible flow pathplanning in accordance with the invention, in particular in order not tolose the flexibility gained in the flow path planning again.

The present invention therefore furthermore includes a method for themonitoring of the then current and/or scheduled state of a plurality ofvalves in the flow path control, in particular in a medical treatmentmachine, having the steps: determining the then current and/or scheduledswitching state of the valves; determining the connections resultingfrom the switching state of the valves; and comparing the resultingconnections with a predetermined number of non-permitted connections.

All the permitted flow paths are therefore no longer stored, which wouldthen have to be revised on a change or a new introduction of a method,but rather all the prohibited paths are determined and stored once forthe total arrangement of the valves, pumps and connections, that is forall the valves, sinks and/or sources of the system. Only the connectionsresulting from the switching state of the valves thus still have to bedetermined and compared with this number of non-permitted connectionsfor the monitoring of the then current and/or scheduled state of thevalves or of the system.

Only connections between the inlets or outlets of the system have to betaken into account as non-permitted connections, e.g. a connectionbetween the terminal leading to the patient and the terminal leading tothe drainage bag. The internal switching state of the valves, whichcorresponds to one of such connections, in contrast no longer has to beclassified as permitted or non permitted since the method determineswhich connections are present between the inlets and outlets of thesystem by the switching state of the valves (and the internalconnections connected thereto). Only these connections between theinlets and outlets of the system then have to be compared with the nonpermitted connections.

The determination of the connections resulting from a switching stateadvantageously always takes place when the switching state of a valvechanges or should change. The valve states are therefore monitored. Ifthe valve state changes or if a process wants to change a valve status,the connections or flow paths resulting from the changed switching stateof the valve are determined and a check is made whether theseconnections or flow paths are non permitted connections or flow paths.

In this connection, all the open valves are advantageously virtuallyflooded, starting from one or more starting points, for thedetermination of the connections resulting from a switching state. Inthis connection, a check is made, starting from one starting point, asto which connections result over the open valves of the system startingfrom this starting point. In this connection, the valves and theconnections resulting through the passages conducting liquid between thevalves are stored, e.g. in the form of a network, in the treatmentmachine.

An open, not yet flooded valve is advantageously respectively selectedas the starting point in this connection. Starting from this open, notyet flooded valve, all the open valves connected to this valve are thenvirtually flooded from which, in turn, all the adjacent open valves areflooded until no further adjacent open valves are found which have stillnot been flooded. At the end of this process, the connection between aplurality of sources and/or sinks established by the respectivelyflooded connections then results. If the system still has further open,not yet flooded valves, the process is continued with one of thesevalves as the starting point to determine all the connectionsestablished by the system.

Advantageously, in this process, in accordance with the invention allthe determined connections are entered in a connection matrix. It can,in particular, be entered into such a matrix for all combinations ofvalves of the total system whether a connection is present between thesetwo valves or not by the then current switching state of the valves. Inthis regard, an iterative procedure can in turn be followed, asdescribed above, in that all the open valves are virtually floodedsequentially, starting from one or more starting points, and theconnections resulting therefore are entered into the connection matrix.

In this way, only the resulting connection matrix has to be comparedwith a control matrix in which all the non permitted connections havebeen entered. If the resulting connection matrix has no entry whichwould correspond to a non permitted connection, the connections providedby the then current and/or scheduled state of the valves are permitted.

If, in contrast, a non permitted connection is recognized for aswitching state of the valves, safety measures are initiated. If themethod recognizes a non permitted connection for a current switchingstate, the system advantageously switches into a safe state. Uponrecognition of a non permitted connection which would result from ascheduled switching state of the valves, this switching state is notbrought about.

In accordance with the invention, an extremely safe method herebyresults for the monitoring of the valves by which it is ensured that nonon permitted flow paths are established. Since the non permitted flowpaths only have to be preset once, the safety system does not have to beadapted to newly implemented processes and thus has the high flexibilityof the system in accordance with the invention.

The present invention furthermore includes a machine, in particular amedical treatment machine, having a plurality of valve actuators for thecontrol of valves for the flow path control, in particular in a cassettesystem, having a valve actuator control and having a monitoring unit forthe monitoring of the then current and/or scheduled state of a pluralityof valves, with the monitoring unit determining the then current and/orscheduled switching state of the valves and the connections resultingfrom the switching state and comparing the resulting connections with apredetermined number of non permitted connections. The machine inaccordance with the invention is in particular equipped with a controlwhich is programmed so that the method in accordance with the inventionfor the monitoring of the valve position is carried out on it, inparticular automatically. Advantageously, the switching state of a valveis determined by the switching state of the associated valve actuator ofthe machine so that the monitoring of the switching state of the valveactuators on the machine side can be used for the monitoring of theswitching state of the valves. The valves themselves are, in contrast,usually components of a cassette which is inserted into the machine as adisposable part.

A flexible capability of reliably monitoring the switching state of thevalve actuators or valves and thus the permissibility of the thencurrent and/or scheduled flow paths thus results with the machine inaccordance with the invention.

The determination of the connections resulting from a switching stateadvantageously always takes place when the switching state of a valvechanges or should change. The machine in accordance with the inventionthus always checks the permissibility of the connections when a valveactuator is controlled or should be controlled.

In this connection, all the open valves are advantageously virtuallyflooded, starting from one or more starting points, for thedetermination of the connections resulting from a switching state. Themachine in accordance with the invention advantageously includes amemory in which a representation of the valves and of the flow paths isstored. The machine furthermore advantageously includes a computing unitwhich carries out a virtual flooding on the basis of these data.

An open, not yet flooded, valve is advantageously respectively selectedas the starting point in this connection. Further advantageously, allthe connections determined are entered into a connection matrix. Forthis purpose, the machine in accordance with the inventionadvantageously has a memory in which the determined connections can bestored.

Further advantageously, the resulting connection matrix is compared witha control matrix in which all non permitted connections have beenentered. The machine in accordance with the invention alsoadvantageously has a memory for this purpose in which the control matrixis stored. The monitoring unit then advantageously compares theresulting connection matrix with the stored control matrix.

In this regard, the machine advantageously switches into a safe state onrecognition of a non permitted connection with a then current switchingstate of the valves and/or does not initiate this switching state onrecognition of a non permitted connection with a scheduled switchingstate. The safety of the machine is hereby guaranteed.

The machine in accordance with the invention advantageously has acoupling surface for the coupling of a cassette, with the cassetteincluding passages having valves and conducting liquids and with thevalve actuators on the machine side for the establishing of differentflow paths in the cassette determining the switching state of the valveson the cassette side.

As described, both the method in accordance with the invention for thecontrol of the valves and the method in accordance with the inventionfor the monitoring of the state of the valves are of great advantageindependently of one another. It is, however, obvious to the skilledperson that particularly the combination of the extremely flexiblecontrol method with the equally flexible monitoring method results inspecial advantages, in particular on the implementation of newprocesses.

The present invention furthermore includes a machine, in particular amedical treatment machine, having a plurality of valve actuators for thecontrol of valves for flow path control, in particular in a cassettesystem, with the machine having a control for the carrying out of one ofthe methods described above. The control in accordance with theinvention is in particular programmed such that one or more of themethods in accordance with the invention can be carried out. The sameadvantages hereby evidently result such as were already described abovewith respect to the method.

Furthermore, the present invention includes a computer program product,in particular a memory medium with a computer program, for transferringto a machine, in particular to a medical treatment machine, withcommands for the carrying out of a method such as are described above.An existing machine, in particular an existing medical treatmentmachine, on which methods in accordance with the prior art havepreviously been used, can be put in a position by such an update tocarry out the methods in accordance with the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in more detail withreference to embodiments and drawings. There are shown:

FIG. 1 is a valve arrangement for whose control and/or monitoringembodiments of the methods in accordance with the invention are used aswell as a legend for the symbols used in the drawings following it.

FIG. 2 a is a first process which is used in an embodiment of the methodin accordance with the present invention for the control of valves.

FIG. 2 b is a second process which is used in an embodiment of themethod in accordance with the present invention for the control ofvalves.

FIG. 3 is a diagrammatic representation of the embodiment of the methodin accordance with the present invention for the control of the valves.

FIG. 4 is a first state of a plurality of valves which is monitored byan embodiment of the method in accordance with the present invention formonitoring valve states.

FIG. 5 is a second state of a plurality of valves which should bemonitored by the embodiment of the method in accordance with theinvention for monitoring valve states.

FIGS. 6 a-6 d are individual steps of the embodiment of the method inaccordance with the present invention for the monitoring of a state.

FIG. 7 is a connection matrix which is used in the embodiment of themethod in accordance with the present invention for the monitoring andwhich corresponds to the state of a plurality of valves shown in FIG. 4.

FIG. 8 is the starting point for a connection matrix as is prepared bythe embodiment of the method in accordance with the invention for themonitoring of the state of a plurality of valves shown in FIG. 5.

FIGS. 9 a-9 d are individual steps in the preparation of a connectionmatrix by the embodiment of the method in accordance with the presentinvention for the monitoring of a state which correspond to the stepsshown in FIGS. 6 a to 6 d.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

In FIG. 1, a valve arrangement is shown for whose control and/ormonitoring the methods in accordance with the invention can be used. Thefluid paths and valves shown are integrated in a disposable cassettewhich is inserted into a treatment machine in accordance with theinvention and is there coupled to a coupling surface. The couplingsurface of the treatment machine has valve actuators which cooperatewith valve points at the cassette and hereby form valves.

The fluid paths in the cassette are formed by liquid conducting regionswhich have flexible walls at least in the region of the valve points.The flexible regions can be pressed by the valve actuators into theregions conducting liquid to close said regions. The cassette inparticular consists of a hard part with liquid conducting passages whichare covered by a flexible foil.

The disposable cassette furthermore has, beside the fluid paths and thevalves, pump chambers PA and Ps which are likewise formed as liquidconducting regions covered by a flexible membrane, with the membranebeing able to be pressed into or out of the cassette by the treatmentmachine so that a pump function results.

In the valve system shown in FIG. 1, a plurality of inlets and outletsare provided which can be connected to one another and/or the pumpchambers via the valves. Connections for liquid bags and for the patientare in particular provided. Each of the connections for external lineshas its own valve. Furthermore, respective valves are provided at theinlets and outlets of the two pump chambers PA and P8.

The pump chambers are thus in communication with the patient connectionvia valves V1, V3 and V6. Furthermore, the pump chambers are incommunication with the liquid bags via valves V2, V4 and V7 to V9. Thepatient connection is likewise directly in communication with the liquidbags via the valve V5. In this connection, in the arrangement shown inFIG. 1, two connections are provided for liquid bags for treatmentliquids as well as one connection for a drainage bag.

The two pump chambers are arranged parallel to one another between acommon line which leads to the liquid bags and a line which leads to thepatient. Furthermore, a line having the valve V5 and parallel to thepump chamber is provided via which a direct connection can beestablished between the patient and the liquid bags.

Embodiments of the methods in accordance with the invention for thecontrol of the valves V1 to V9 as well as for their monitoring will nowbe described in more detail with reference to FIGS. 1 to 9. For thispurpose, the symbols shown in FIG. 1 will be used for the differentswitching states of the valves. A valve filled in in white stands for anon-participating valve whose switching state with respect to thecorresponding method is not defined. A valve filled in in black standsfor a closed valve; a valve filled with diagonal hatching stands for anopen valve. A valve filled with vertical hatching, in contrast, standsfor an open valve which has been virtually flooded for the method.

In this connection, a starting position of a method for controllingvalves for flow path control of a medical treatment machine is shown inFIG. 1. All the valves are initially non participating, that is they canbe mechanically open or closed. Since a certain starting status isrequired for the control of the flow paths, the valves are initiallyclosed in the embodiment.

The embodiment of the method in accordance with the invention includes aplurality of processes for the establishing of flow paths by the controlof a group of valves, with each process claiming the respectivelyrequired group of valves for itself during its carrying out so thatother processes cannot control these valves. In FIG. 2 a, a firstprocess 8 is shown which establishes the flow path from the patient tothe pump P8. The valves V1, V4 and V5 are closed for this purpose, whilethe valves V3 and V6 are open. All other valves remain nonparticipating. The process shown in FIG. 2 a thus claims the valves V1,V3 and V4 to V6 for itself so that other processes cannot change theswitching state of these valves.

In FIG. 2 b, a second process A is now shown by which a flow path fromthe patient to the pump chamber PA should be established. For thispurpose, the valves V2, V3 and V5 are closed and the valves V1 and V6are open, while the other valves remain non participating. The secondprocess A thus requires the valves V1 to V3 as well as V5 and V6. Withthe exception of the valve V2, however, all these valves are stillreserved by the first process 8 so that process A cannot control them.The valve V3 reserved by the first process is in particular in its openposition, while it would have to be closed for the second process. Thequery made by the second process whether the valves required for theestablishing of the desired flow path are available thus has the resultthat the required valves are partly reserved by another process sincevalve 3 is claimed by the first process and its switching position wouldhave to be changed.

The second process thus initially only reserves the already availablevalves which are needed to provide the fluid path, i.e. the stillunclaimed valve V2 and the valves V1, V5 and V6 which are claimed by thefirst process and which are already in the switching state required bythe second process, and makes a request to the first process so that itreleases the valves still needed. The first process then decides whetherand when it will release the required valves, i.e. the valve V3 whichwould have to be switched over. The second process must wait so long.The decision of the first process on the release of the requested valvescan be influenced by its own process criteria such as the pump positionor by external circumstances such as a higher prioritization of theother process. It is, however, decisive in this connection that only thefirst process can release the valves used by it. A cooperation of theprocess is hereby ensured which is as safe as it is coordinated. Inaccordance with the invention, accordingly only the process which hasclaimed a specific valve at the then current time can also release itagain.

The procedure of the routine of the method in accordance with theinvention for the control of the valves will be presented in more detailagain with reference to the process diagram shown in FIG. 3. The process1 has established a certain flow path and claims a first group of valvesfor this purpose. The second process 2 now first polls the availabilityof a second group of valves by whose control a second flow path shouldbe established. This polling of the available valves simultaneouslyrepresents a request to the central valve control to associate thesevalves with the second process. In this connection, the second processcan, however, only claim those valves for itself by its poll which areavailable. The second process can only obtain a claim right from thevalve control for the polled valves which are not available so that itcan claim these valves for itself when they are released. It can herebybe prevented that a third process claims the valves required by thesecond process, but not yet released, for itself when they are released.

The second process now signals to the first process via the valvecontrol with respect to the polled but not yet available valves and thusrequests the first process to release the required valves. The process 1can here detect, e.g. with the help of a status query (polling), thatthe valves are needed and the flow path formed by process 1 should becancelled. The first process can now make a free decision on how toproceed. In particular only the first process makes a decision on therequest whether the valves requested by the second process and claimedby the first valves will be released or not. If the first processreleases the valves, it reports this to the central valve control. Allthe valves required for the second process are hereby available so thatit can be carried out. The second process now for its part claims thecorresponding group of valves to provide the desired flow path.Accordingly, now only the second process can also make a decision on afurther query of another process on the extent to which the valvesclaimed by it will be released again.

An extremely flexible control of the valves by which all the valves ofthe system can be used to the optimum thus results from the method inaccordance with the invention for the control of the valves for thefluid path control. The valves in this connection represent a resourcefor the flow paths to be formed since a flow path is described by anarrangement of open and closed valves. A flow path can therefore only becarried out when all the resources are available, that is when all thevalves participating in the flow path are available for thecorresponding process.

The valve control in accordance with the invention permits the effectivescheduling of the available resources in that it provides individualfunctionalities to the individual processes. A process for the provisionof a flow path can request resources, that is claim available valves foritself, whereby they are no longer available to other processes, orrelease valves claimed for themselves again, whereby they are againavailable to other processes. Furthermore, individual processes canquery the cancellation of another flow path (signaling) in order thus toclaim required valves for itself. Processes can equally poll whether theflow path established by it should be cancelled (flow path status), e.g.because other processes have a higher priority. The decision on thecancellation of the flow path or on the release of the valvesparticipating therein, however, is always made by the process which isutilizing the resources to be released.

A possibility which is simple to implement hereby results ofsynchronizing a plurality of processes with one another, e.g. to controla plurality of pumps, without impairing the safety of the total system.

The logic of the safety system of the treatment machine in accordancewith the invention is also inverted for the described flexible flow pathscheduling. In this connection, all the allowed flow paths are no longerstored which would then have to be revised on a change or a newintroduction of a process, but rather all the prohibited paths aredetermined and stored at one time for the total arrangement of thevalves, pumps and connections.

The present invention has a method for the monitoring of the state ofthe valves in the flow path control for this purpose. All the valvestates are monitored for this purpose. If a valve status changes or if aprocess plans a change in valve status, all the connections aredetermined which result from the then current or scheduled switchingstate of the valves. The connections established in this context arethen compared with the predetermined number of non permitted connectionsto recognize non permitted connections and thus non permitted switchingstates.

To determine the connections which result from a switching state of thevalves, all the open valves are virtually flooded, starting from one ormore positions, and the result of the flooding is entered into aconnection matrix. A check can now be made directly from the connectionmatrix produced in this manner whether a prohibited path stored with theprotective system is used or should be used.

In this connection, a first switching state of the valves is shown inFIG. 4 in which the valves V3, V6 and V9 are open and the remainingvalves are closed. The patient is hereby connected to the pump chamberPs. This state corresponds to the connection matrix shown in FIG. 7 inwhich a connection is only present between the valve V3 and the valveV6. The likewise open valve V9 is not connected to any further openvalves so that this open valve is no longer considered in the connectionmatrix.

If now a change should be made from the switching state shown in FIG. 4to the switching state shown in FIG. 5 in that the valve V4 is opened,the method in accordance with the invention for the monitoring of thescheduled state of the valves checks whether a non permitted connectionhereby results.

In this connection, a still empty connection matrix is first assumedsuch as is shown in FIG. 8. By a virtual flooding of all open valves,all the connections which result from the state of the valves shown inFIG. 5 are now entered step by step. Connections between two valves Vxand Vy are marked in the connection matrix by an entry in the field ofthe matrix associated with the combination of the valves Vx and Vy. Forthe sake of clarity, connections are only shown in the bottom left halfof the matrix in the connection matrices shown in FIGS. 7 to 9. Thefields in the top right half are equivalent thereto.

The method for the determination of the connections arising from aswitching state of the valves by means of a virtual flooding will now bedescribed with reference to FIGS. 6 a to 6 d as well as to theassociated resulting connection matrices 9 a to 9 d.

For this purpose, first a still not flooded, open valve is selected andvirtually flooded in the state of the valves shown in FIG. 5. In theexample shown, as illustrated in FIG. 6 a, the valve V3 is firstflooded. The corresponding selection is shown in FIG. 9 a by thecircling of the field in the connection matrix associated with the valveV3 itself. Starting from the valve V3 and as shown in FIGS. 6 b and 6 c,all the open valves adjacent to the valve selected as the starting pointare flooded. The valve V4 is therefore flooded in FIG. 6 b and valve V6in FIG. 6 c.

The connections resulting from this flooding are stored in theconnection matrix. As shown in FIG. 9 b, the connection established byflooding the valve V4 between the valves V3 and V4 is thus first storedin the connection matrix by a marking of the corresponding field. Aconnection is now first produced by the flooding of the valve V6likewise adjacent to the valve V3 shown in FIG. 6 c between the valvesV3 and V6 which is first entered in the first connection matrix shown inFIG. 9 c. The system now checks whether further connections betweenvalves are produced by this new connection. In the embodiment, aconnection is produced in this context by the connection of the valve V3to the valve V6, on the one hand, and to the valve V4, on the otherhand, between the valve V6 and the valve V4, said connection now beingentered in a second step, as shown in second in FIG. 9 c, into theconnection matrix.

The method now continues to flood further open valves adjacent to thealready flooded valves. In this connection, no further open unfloodedvalve is adjacent to the valve V6 so that the method ceases here. Theopen valve V9 still unflooded in FIG. 6 c, in contrast, is adjacent tothe flooded valve V4 and is now likewise flooded in the next step whichis shown in FIG. 6 d. A connection between the valve V4 and the valve V9hereby first results which is now entered into the connection matrix ina first step. This is illustrated in the first connection matrix shownin FIG. 9 d. However, due to the already present connection between thevalve V4 and V3, the new connection between the valve V9 and V3 is nowalso produced which is now entered into the connection matrix in asecond step. Furthermore, due to the already present connection betweenthe valve V6 and the valve V3 or the valve V4, a new connection isproduced between the valve V9 and the valve V6 which is now likewiseentered into the connection matrix in the last step.

After all the open valves connected to the valve selected as thestarting point have been flooded and all the connections generatedthereby have been entered into the connection matrix, the system checkswhether further open valves which are still unflooded are present. Ifthe system finds such a valve, it is selected as the starting point fora further virtual flooding which runs according to the same pattern. Thesystem repeats this procedure for so long until all the open valves havebeen flooded.

All the connections which are produced by the examined state of thevalves have now been entered in the connection matrix resulting fromthis virtual flooding.

The connection matrix is now compared with a control matrix in which allthe non permitted connections have been entered. Such a control matrixe.g. includes the non permitted connection between the valves V9 and V6by which a connection would be established between the patient and thedrainage. The method in accordance with the invention thus recognizes,with reference to the connection matrix which is shown at the far rightin FIG. 9 d and which is determined for the state shown in FIG. 5, thata non permitted connections would be established by this state.Accordingly, the safety system in accordance with the invention preventsa switch being made into this state. If, in contrast, a then currentswitching state is checked by the safety system and it is found that anon permitted connection is present, the system automatically switchesinto a safe state.

In this connection, only non permitted connections have to be givenbetween the terminals, i.e. between the valves V6 to V9. How theseconnections are realized is, in contrast, not relevant to theevaluation. All the permitted switching states of all valves thus nolonger have to be stored in the safety system, but rather only the nonpermitted connections between terminals, whereas the systemindependently checks whether a specific switching state results in sucha non permitted connection. It would be conceivable to store thepermitted connections between the terminals in the safety systemalternatively to the non permitted connections. All the permittedswitching states would then also not have to be stored in the system.Since, however, considerably more permitted connections than nonpermitted connections are present, the storing of the non permittedconnections is more effective.

The present invention furthermore includes, in addition to the shownembodiments of the methods, a treatment machine, in particular forperitoneal dialysis, in whose control the corresponding methods areimplemented. The present invention furthermore includes a computerprogram product, in particular a storage medium, on which correspondingcontrol software is stored which can be transferred to correspondingtreatment machines to implement the methods in accordance with theinvention there.

The invention being thus described, it will be apparent that the samemay be varied in many ways. Such variations are not to be regarded as adeparture form the spirit and scope of the invention, and all suchmodifications as would be recognized by one skilled in the art areintended to be included within the scope of the following claims.

What is claimed is:
 1. A method for controlling valves for flow pathcontrol in a machine having a plurality of processes for establishingflow paths by controlling a plurality of valves that, before beingclaimed by a particular process, are available to, and controllable by,more than one process, said method comprising the steps of a firstprocess claiming or taking control of a group of valves from saidplurality of valves and setting a switching state of said group ofvalves, said switching states creating connections between the valves toestablish a flow path for executing the first process before said firstprocess is executed; comparing the connections defining said flow pathwith a plurality of connections previously identified as non-permittedconnections; in a presence of a non-permitted connection, the machinegoing into a safety state in which the switching states identified ascreating a non-permitted connection are prevented; in an absence ofnon-permitted connections, permitting the switching states to create theflow path and performing the first process, said claimed valves beingnon-available to other processes while said valves are claimed by saidfirst process and other processes being unable to change the switchingstate of said claimed valves while said valves are claimed by said firstprocess; polling by a second process of a valve being used in said firstprocess resulting in a request to the first process claiming saidnon-available valve for a release of said non-available valve, saidfirst process itself making a decision on said request for the releaseof the non-available valve claimed by said first process; and thecurrent and scheduled switching states of the valves being monitoredduring performance of said plurality of processes by said machine toavoid a flow path having a non-permitted connection.
 2. The method inaccordance with claim 1, wherein said non-available valve, if releasedby said first process, is controllable by said second process, saidsecond process being executed when all required valves are available. 3.The method in accordance with claim 1, wherein each process makes adecision on the release of the valves claimed by it in dependence on atleast one of internal and external process criteria.
 4. The method inaccordance with claim 1, wherein each process releases the claimed groupof valves after execution is complete.
 5. The method in accordance withclaim 1, wherein a process can claim different groups of valves fromwithin said plurality of valves depending on the availability of thevalves.
 6. The method in accordance with claim 1, wherein each processpolls the availability of a group of valves suitable for executing aprocess before executing said process.
 7. The method in accordance withclaim 6, wherein a process is carried out when a suitable group ofvalves is available, with the process claiming this group of valves foritself.
 8. The method in accordance with claim 1, wherein a plurality ofconnections resulting from different switching states of the valves isdetermined by flooding open valves from at least one starting point andstoring resulting connections in a connection matrix.
 9. The method inaccordance with claim 8, wherein the step of comparing connections witha plurality of previously identified connections includes comparing theconnection matrix with a control matrix that contains non-permittedconnections.
 10. The method in accordance with claim 1, furthercomprising a central valve association process in which all of saidplurality of processes are able to claim, release and poll requiredvalves.
 11. A machine having a plurality of processes for establishing aplurality of flow paths comprising: a plurality of valve actuators forcontrolling valves to establish flow paths, said valve actuators in saidplurality of valve actuators, before being claimed by a particularprocess, being available to, and controllable by, more than one process;a valve actuator control for executing a plurality of processes forestablishing said flow paths by controlling a group of said plurality ofvalve actuators, the valve actuator control being configured such that afirst process polls an availability of a group of valve actuators fromsaid plurality of valve actuators to establish a first flow pathsuitable for said first process to execute a first one of said pluralityof processes; said first process configured to control said group ofvalve actuators that are determined to be available for execution ofsaid first one of said plurality of processes, said first processsetting switching states for said group of valve actuators, saidswitching states creating connections between the valve actuators toestablish the first flow path; said machine configured to compare theconnections that define said first flow path with a plurality ofconnections previously identified as non-permitted connections, saidmachine upon detection of a non-permitted connection being furtherconfigured to enter a safety state in which the switching statesidentified as creating the non-permitted connection are prevented; in anabsence of non-permitted connections, said machine configured to permitthe switching states to create the first flow path and perform the firstprocess, said claimed valve actuators being unavailable to otherprocesses while said valve actuators are controlled by said firstprocess and other processes being prevented from changing the switchingstate of said claimed group of valve actuators; said valve actuatorcontrol being further configured such that a second process is able topoll valve actuators for controlling a second group of valves forperforming a second process, polling of a non-available valve actuatorby said second process resulting in a request to the first processclaiming the non-available valve actuator to release the non-availablevalve actuator, with only the first process making a decision on thisrelease request; and said machine monitoring the current and scheduledswitching states of the valve actuators to avoid a non-permittedconnection.
 12. The machine in accordance with claim 11, wherein saidnon-available valve, if released by said first process, is controllableby said second process, said second process being executed when allrequired valves are available, each process making a decision on releaseof the valve actuators claimed by it in dependence on at least one ofinternal and external process criteria.
 13. The machine in accordancewith claim 11, further comprising: a connection matrix for storing aplurality of connections resulting from a valve actuator switchingstate; and a control matrix containing non-permitted connections; saidmachine being configured to compare the connection matrix with thecontrol matrix when establishing a flow path to avoid switching statesthat result in use of a non-permitted connection.
 14. The machine inaccordance with claim 11, wherein each process releases the claimedgroup of valve actuators after execution is completed.
 15. The machinein accordance with claim 11, wherein a process can claim differentgroups of valve actuators from within said plurality of valve actuatorsin dependence on an availability of the valve actuators.
 16. The machinein accordance with claim 11, wherein each process polls for availabilityof a group of valve actuators suitable for execution of a process beforeexecution thereof.
 17. The machine in accordance with claim 11, whereineach process polling for valve actuators receives a claiming right forall polled but not available valve actuators on the polling so that theprocess that is polling can claim these valve actuators for itself whensaid polled but not available valve actuators have been released. 18.The machine in accordance with claim 11, wherein the valve actuatorcontrol includes a central valve association process in which all theother processes are able to claim, release and poll required valveactuators.
 19. The machine in accordance with claim 11, having a machineside with a coupling surface for coupling of a cassette, said cassettecomprising valves and liquid conducting passages, wherein the valveactuators on the machine side determine a switching state of the valveson the cassette to establish different flow paths.
 20. The machine inaccordance with claim 11, having a coupling surface for coupling of acassette which comprises valves and liquid conducting passages, whereinthe valve actuators on the machine determine a switching state of thevalves on the cassette to establish different flow paths in thecassette.
 21. A computer program product comprising a non-transitorystorage media, having a computer program for transfer to a machine, saidprogram having commands for controlling a plurality of valves to controlflow paths in a medical treatment machine that has a plurality ofprocesses for establishment of flow paths by controlling a group ofvalves from said plurality of valves and setting a switching state ofsaid group of valves, said valves in said plurality of valves, beforebeing claimed by a particular process, being available to, andcontrollable by, more than one process, said program configured toenable a first process to take control of a group of valves from saidplurality of valves and set switching states for said group of valves,said switching states creating connections between the valves toestablish a flow path for executing the first process before said firstprocess is executed; said program further configured to compare theconnections defining said flow path with a plurality of connectionspreviously identified as non-permitted connections; in a presence of anon-permitted connection, the program initiating a safety state in whichthe switching states identified as creating a non-permitted connectionare prevented; in an absence of non-permitted connections, the programpermitting the switching states to create the flow path and perform thefirst process, said claimed valves being non-available to otherprocesses while said valves are claimed by said first process and otherprocesses being unable to change the switching state of said claimedvalves while said valves are claimed by said first process; said programconfigured so that polling by a second process of a valve being used insaid first process results in a request to the first process claimingsaid non-available valve for a release of said non-available valve, saidfirst process itself making a decision on said request for the releaseof the non-available valve claimed by said first process; and saidprogram operating to monitor the current and scheduled switching statesof the valves during performance of said plurality of processes by saidmachine to avoid a flow path having a non-permitted connection.